In the study, the researchers looked at 20 people whose average age was 27. In a pair of testing visits, the participants were given either a placebo or a nitrate supplement sourced from beetroot juice. The researchers then measured their heart rate, blood pressure and muscle sympathetic nerve activity. Their muscle activity was measured at rest and then while performing a hand grip exercise using their non-dominant hand. This was measured again after they drank the beetroot juice or the placebo and rested for three hours.